Standby power supply device and standby power supply system

ABSTRACT

A standby power supply device includes at least one port, at least one current detection unit, a power supply unit, and a control unit. Each port is configured to connect to an external powered device. A current detection unit is connected to one port. Each current detection unit detects the current of the port. When the current of one port exceeds a first predetermined value, the current detection unit outputs a first detection signal. The power supply unit supplies standby power to an external powered device. The control unit controls the power supply unit supply power to the external powered device when the control unit receives the detection signal from the corresponding current detection unit. When the control unit receives multiple first detection signals, the control unit controls the power supply unit to supply power to multiple external powered devices simultaneously.

FIELD

The subject matter herein generally relates to a standby power supply,and particularly to a one-to-many standby power supply device andsystem.

BACKGROUND

The N: 1 standby power supply system provides a backup power to Ndevices (such as switches) through an external backup power supply.Under normal circumstances, all device loads are powered primarily bytheir internal power source, and the standby power is close to a no-loadstate. If one of the devices has a power failure, the standby powersupply can immediately supply power to the device. Such system onlyprovides a backup power to only one of the faulty device, and formultiple faulty devices, the system can only supply power to the highestpriority single device. Improvement in the art is preferred.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present disclosure will now be described, by wayof example only, with reference to the attached figures.

FIG. 1 is a block diagram of an exemplary embodiment of a standby powersupply device 10 a.

FIG. 2 is a block diagram of another exemplary embodiment of the standbypower supply device 10 b.

FIG. 3 is a circuit diagram of an exemplary embodiment of a currentdetection unit.

FIG. 4 is a mode conversion diagram of the standby power supply deviceof FIG. 2.

FIG. 5 is a circuit diagram of an exemplary embodiment of the currentdetection unit.

FIG. 6 is a block diagram of an exemplary embodiment of a standby powersupply system.

FIG. 7 is an effect diagram of an exemplary embodiment of a standbypower supply system.

FIG. 8 is an effect diagram of another exemplary embodiment of a standbypower supply system.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration,where appropriate, reference numerals have been repeated among thedifferent figures to indicate corresponding or analogous elements. Inaddition, numerous specific details are set forth in order to provide athorough understanding of the exemplary embodiments described herein.However, it will be understood by those of ordinary skill in the artthat the exemplary embodiments described herein can be practiced withoutthese specific details. In other instances, methods, procedures, andcomponents have not been described in detail so as not to obscure therelated relevant feature being described. Also, the description is notto be considered as limiting the scope of the exemplary embodimentsdescribed herein. The drawings are not necessarily to scale and theproportions of certain parts have been exaggerated to better illustratedetails and features of the present disclosure.

Several definitions that apply throughout this disclosure will now bepresented.

The term “coupled” is defined as connected, whether directly orindirectly through intervening components, and is not necessarilylimited to physical connections. The connection can be such that theobjects are permanently connected or releasably connected. The term“comprising,” when utilized, means “including, but not necessarilylimited to”; it specifically indicates open-ended inclusion ormembership in the so-described combination, group, series, and the like.

The disclosure is described in relation to a standby power supply deviceand a standby power supply system.

FIG. 1 illustrates an exemplary embodiment of a standby power supplydevice (standby power supply device 10 a). In at least one exemplaryembodiment, the standby power supply device 10 a supplies power to anexternal powered device 20 when the external powered device 20 ispowered off. In at least one exemplary embodiment, the standby powersupply device 10 a comprises at least one port 100, at least one currentdetection unit 102, a control unit 103, and a power supply unit 104.

Each of the at least one port 100 is configured to access the externalpowered device 20. The power supply unit 104 supplies power to theexternal powered device 20. When the external powered device 20 sufferspower off, the power supply unit 104 supplies power to the externalpowered device 20 from a corresponding port 100. When multiple externalpowered devices 20 suffer from power loss, the power supply unit 104supplies power simultaneously to multiple powered devices fromcorresponding ports 100.

Each of the at least one current detection unit 102 is coupled to one ofthe at least one port 100. The current detection unit 102 detectscurrent of a corresponding port 100. When the external powered device 20is powered off, the current of the corresponding port 100 increases.When the current of one at least one port 100 exceeds a firstpredetermined value, the corresponding current detection unit 102outputs a first detection signal. The control unit 103 is coupled to thecurrent detection unit 102 and the power supply unit 104. The controlunit 103 controls the power supply unit 104 to supply power to thepowered device 20 when the control unit 103 receives the first detectionsignal. The control unit 103 can supply power to multiple externalpowered devices 20 simultaneously when the control unit 103 receivesmultiple first detection signals.

FIG. 2 illustrates an exemplary embodiment of a standby power supplydevice 10 b. The standby power supply device 10 b is similar to thestandby power supply equipment 10 a in FIG. 1. In at least one exemplaryembodiment, the standby power supply device 10 b comprises a port 100 a,a port 100 b, and a port 100 c (only three being shown as a non-limitingexample), a current detection unit 102 a, a current detection unit 102b, a current detection unit 102 c (three are shown), the control unit103, and the power supply unit 104.

In at least one exemplary embodiment, the control unit 103 furthercomprises a port management unit 1031 a, a port management unit 1031 b,a port management unit 1031 c, a power calculation unit 1033, and aprocessing unit 1032. The port management units 1031 a-1031 c arecoupled to ports 100 a-100 c. The port management units 1031 a-1031 cobtain the power of the external powered devices 20 a-20 c from theports 100 a-100 c, and obtain priority level information of the externalpowered devices 20 a-20 c. The processing unit 1032 is coupled to theport management units 1031 a-1031 c and the current detection units 102a-102 c. The power supply unit 103 selectively supplies power to theexternal powered devices 20 a-20 c or one or two of the external powereddevices 20 a-20 c when the processing unit 1032 receives the firstdetection signal from the current detection units 102 a-102 c. Forexample, the processing unit 1032 supplies power to the external powereddevice 20 a when the processing unit 1032 receives the first detectionsignal from the current detection unit 102 a. The processing unit 1032can also supply power to the external powered devices 20 b-20 c when theprocessing unit 1032 receives the first detection signal from thecurrent detection units 102 b-102 c. The power calculation unit 1033 iscoupled to the power information unit 1041 and the port management units1031 a-1031 c. In at least one exemplary embodiment, the power supplyunit 104 further comprises a power information unit 1041. The powerinformation unit 1041 is coupled to power calculation unit 1033. Thepower information unit 1041 provides power of the power supply unit 103to power calculation unit 1033. The power calculation unit 1033 isconfigured to calculate an amount of surplus power according to thepower of the power supply unit 104 and the power requirement of theexternal powered devices 20 a-20 c, and further configured to determinewhether the power supply unit 103 continues to supply power to asubsequent external powered device according to the amount of surpluspower.

When the processing unit 1032 receives the multiple first detectionsignals, the processing unit 1032 controls the power supply unit 104 tosupply power to preferentially supply power to an external powereddevice with a highest priority level.

In at least one exemplary embodiment, power supply unit 1041 providessurplus power according to binary encoding. Binary 111 represents power700 W, binary 110 represents power 600 W, and so on, binary 000representing power 0 W. In the exemplary embodiment, the total power ofthe power supply unit 104 is 111 (700 W). When 200 W power is consumed,the surplus power of the power supply unit 104 is 101 (500 W). Theprocessing unit 1032 determines the surplus power of the power supplyunit 104 by receiving the binary code, to determine whether the powersupply unit 104 can continue to supply power to a subsequent externalpowered device.

In at least one exemplary embodiment, the standby power supply device 10b further comprises an electrical switch 101 a, an electrical switch 101b, and an electrical switch 101 c. The electrical switches 101 a-101 care respectively coupled to the ports 100 a-100 c corresponding. Theelectrical switches 101 a-101 c are further coupled to the portmanagement units 1031 a-1031 c and the power supply unit 104. The portmanagement unit 1031 a-1031 c are further configured to control theelectrical switches 101 a-101 c to turn on or turn off. When the port100 a is accessing the external powered device 20 a, the electricalswitch 101 a is turned on, and the power supply unit 104 is coupled tothe port 100 a, thus the port 100 a operates in a standby mode. When theport 100 a does not have access to the external powered device 20 a, theelectrical switch is turned off. The ports 100 b-100 c are similar tothe port 100 a.

In at least one exemplary embodiment, the ports 100 a-100 c are coupledto the external powered devices 20 a-20 c, resulting in the electricalswitches 101 a-101 c being turned on and the power supply unit 104 beingcoupled to the ports 100 a-100 c. When the power sources of externalpowered devices 20 a-20 c are work normally, the ports 100 a-100 coperate in the standby mode and the power supply unit 104 is close tothe no-load state. When the power source of one of the external powereddevices 20 a-20 c is working abnormally or is removed, for example, whenthe power source of the external powered device 20 a is removed, thecurrent of the port 100 a increases. When the current detection unit 102a detects that the current of the first port 100 a exceeds the firstpredetermined value, the current detection unit 102 a outputs the firstdetection signal to the processing unit 1033, resulting in the portmanagement unit 1031 a keeping the electrical switch 101 a on. Thus, thepower supply unit 104 supplies power to the external powered device 20 aand the port 100 a operates in the powering mode. Similarly, when thepower sources of multiple external powered devices, for example theexternal powered device 20 b and the external powered device 20 c, areworking abnormally, the current detection units 102 b-102 c output thefirst detection signal to the control unit 103, resulting in the portmanagement units 1031 b-1031 c keeping the electrical switches 101 b-101c on, and the power supply unit 104 can supply power to the externalpowered devices 20 b-20 c. Thus the standby power supply device 10 b cansupply power to multiple powered devices simultaneously.

In at least one exemplary embodiment, when the processing unit 1032determines that the surplus power of the power supply unit 104 is notenough to supply power to a subsequent external powered device, the portmanagement unit controls the electrical switch corresponding to thesubsequent powered device to be turned off, resulting in thecorresponding port operating in a closed mode. For example, the totalpower of the power supply unit 104 is 700 W, and the ports 100 a-100 caccess the external powered devices 20 a-20 c. The power requirement ofthe external powered device 20 a is 500 W and the power requirement ofthe external powered device 20 b and the external powered device 20 c is300 W. When the power source of the external powered device 20 a isworking abnormally, the power supply unit 104 provides 500 W power tothe external electrical device 20 a, thus the surplus power of the powersupply unit 104 is 200 W. The surplus power of the power supply unit 104is not enough to supply power to the external powered device 20 b or theexternal powered device 20 c, thus, the port management units 1031b-1031 c control the electrical switch 101 b and the electrical switch101 c to turn off, resulting in the port 100 b and the port 100 coperating in the closed mode. When the power source of the externalpowered device 20 a returns to normal, the surplus power of the powersupply unit 104 is changed from 200 W to 700 W. The surplus power of thepower supply unit 104 is now enough to power the external powered device20 a, the external powered device 20 b, or the external powered device20 c, thus, the port management unit 1031 b-1031 c controls theelectrical switch 101 b and the electrical switch 101 c to turn on,resulting in the port 100 b and the port 100 c operating in the standbymode.

In at least one exemplary embodiment, the electrical switches 100 a-100c can be field effect transistors, and the control unit 103 outputs thecontrol signal to control the field effect transistors to turn on or toturn off.

In at least one exemplary embodiment, when one of the current detectionunits 102 a-102 c, for example, the current detection unit 102 a,detects that the current of the port 100 a exceeds the secondpredetermined value, the current detection unit 102 a outputs the seconddetection signal to the port management unit 1031 a. The port 100 aoperates in a overload mode. When the port management unit 1031 areceives the second detection signal, port management unit 1031 acontrols the electrical switch 100 a to turn off. Thus, the port 100 aoperates in a shutdown mode to prevent the power supply unit 104 fromcontinuing to supply power to the external powered device 20 a when thepower source of the external powered device 20 a works normally.

Similarly, when more than one of the current detection units 102 a-102c, for example, the current detection units 102 b-102 c, detect that thecurrent of the ports 100 b-100 c exceed the second predetermined value,the current detection units 102 b-102 c output the second detectionsignals to the port management units 1031 b-1031 c. The ports 100 b-100c operate in the overload mode. When the port management units 1031b-1031 c receive the second detection signal, the port management units1031 b-1031 c control the electrical switches 100 b-100 c to turn off,resulting in the ports 100 b-100 c operating in the shutdown mode. Inthe exemplary embodiment, the first predetermined value and the secondpredetermined value are set in accordance with the power requirements ofthe external powered devices 20 a-20 c.

In at least one exemplary embodiment, each of the current detectionunits, for example, the current detection unit 102 a, comprises anobtaining unit 1021, an amplifying unit 1022, a first comparing unit1023, and a second comparing unit 1024. The obtaining unit 1021 iscoupled to the port 100 a to obtain the current of the port 100 a. Theamplifying unit 1022 is coupled to the obtaining unit 1021 to amplifythe current from the obtaining unit 1021. The first comparing unit 1023is coupled to the amplifying unit 1022, the processing unit 1032, andthe port management 1031 a. The first comparing unit 1023 outputs thefirst detection signal to the port management 1031 a when the currentexceeds the first predetermined value. The second comparing unit 1024 iscoupled to the amplifying unit 1022 and the port management 1031 a. Thesecond comparing unit 1024 outputs the second detection signal to portmanagement 1031 a when the current exceeds the second predeterminedvalue.

FIG. 3 illustrates a circuit diagram of an exemplary embodiment of thecurrent detection unit. In at least one exemplary embodiment, when thecurrent of port 100 is less than the first predetermined value, the port100 operates in the standby mode. When the current of the port 100exceeds the first predetermined value and is less than the secondpredetermined value, the port 100 operates in the power supplying mode.When the current of the port 100 exceeds the second predetermined value,the port 100 operates in the overload mode, then operates in the closedmode.

FIG. 4 illustrates a mode conversion diagram of a standby power supplydevice. In at least one exemplary embodiment, when the external powerdevice 20 is connected to the port 100, the electrical switch 101 turnson, then the port 100 operates in the standby mode. When the processingunit 1032 receives the first detection signal, the external powereddevice 20 is powered off, and the surplus power is enough to supplypower to the external powered device 20. The electrical switch 101 iskept on, then the port 100 operates in the powering mode. When the powersupply of the external powered device 20 is restored, the operating modeof the port 100 is changed from the powering mode to the standby mode.When the processing unit 1032 receives the first detection signal (theexternal powered device 20 is powered off) and the surplus power is notenough to supply power to the external powered device 20, the electricalswitch 101 turns off, then the port 100 operates in the closed mode.When the processing unit receives the second detection signal, the port100 operates in the overload mode, then the electrical switch 101 turnsoff, resulting in the port 100 operating in the closed mode. When theduration of the electrical switch 101 being turned off exceeds a firstpredetermined time, the port management unit 1031 controls theelectrical switch 101 to turn on, resulting in the port operating in thestandby mode.

FIG. 5 illustrates a circuit diagram of an exemplary embodiment of theelectrical current detection unit. In at least one exemplary embodiment,the obtaining unit 1021 comprises a resistor R0. The amplifying unit1022 comprises a first resistor R1 with a first resistor first end and afirst resistor second end, a first capacitor C1 with a first capacitorfirst end and a first capacitor second end, and a second capacitor C2with a second capacitor first end and a second capacitor second end. Theamplifying unit 1022 also has a second resistor R2 with a secondresistor first end and a second resistor second end, and a thirdresistor R3 with a third resistor first end and a third resistor secondend. The amplifying unit 1022 also has a first amplifier OP1 with afirst amplifier first input, a first amplifier second input, and a firstamplifier output. The first resistor first end is coupled to theobtaining unit 1021. The first capacitor first end is coupled to thefirst resistor second end, and the first capacitor second end isgrounded. The second capacitor first end is coupled to the firstcapacitor first end. The second resistor first end is grounded, and thesecond resistor second end is coupled to the second capacitor secondend. The first amplifier first input is coupled to the second capacitorfirst end, and the first amplifier second input is coupled to theconnection point between the second resistor R2 and the second capacitorC2. The third resistor first end is coupled to the first amplifiersecond input, and the third resistor second end is coupled to the firstamplifier output.

In at least one exemplary embodiment, the first comparing unit 1023comprises a fourth resistor R4 with a fourth resistor first end and afourth resistor second end, and a fifth resistor R5 with a fifthresistor first end and a fifth resistor second end. The first comparingunit 1023 also comprises a first switch resistor Rp1 with a first switchresistor first end and a first switch resistor second end, a secondswitch resistor Rp2 with a second switch resistor first end and a secondswitch resistor second end, and a third switch resistor Rp3 with a thirdswitch resistor first end and a third switch resistor second end. Thefirst comparing unit 1023 also comprises a fourth switch resistor Rp4with a fourth switch resistor first end and a fourth switch resistorsecond end, and a first Single-Pole-Four-Throw switch S1 (SPFT switch).The first comparing unit 1023 also comprises a third capacitor C3 with athird capacitor first end and a third capacitor second end, a fourthcapacitor C4 with a fourth capacitor first end and a fourth capacitorsecond end, and a fifth capacitor C5 with a fifth capacitor first endand a fifth capacitor second end. A first comparator CP1 with a firstcomparator first input, and a first comparator second input and a firstcomparator output are also comprised in unit 1023. The fourth resistorfirst end is coupled to the amplifying unit 1022. The fifth resistorfirst end is coupled to a first reference voltage VCC1, and the fifthresistor second end is coupled to the third capacitor first end. Thethird capacitor second end is grounded. The first reference voltage VCC1is further coupled to the first switch resistor first end, the secondswitch resistor first end, the third switch resistor first end, and thefourth switch resistor first end. The first SPFT switch S1 comprises afirst SPFT switch first pin module S11, a first SPFT switch second pinmodule S12, and a first SPFT switch control end S13. The first SPFTswitch first pin module S11 is coupled to the first switch resistorsecond end, the second switch resistor second end, the third switchresistor second end, and the fourth switch resistor second end. Thefirst SPFT switch second pin module S12 is coupled to the fourthcapacitor first end, and the fourth capacitor second end is coupled tothe fifth capacitor first end. The fifth capacitor second end isgrounded. The first SPFT switch control end S13 is coupled to thecontrol unit 10. The first comparator first input is coupled to thefourth capacitor first end, the first comparator second end is coupledto a connection point between the fourth capacitor C4 and the fifthcapacitor C5, and the first comparator output is coupled to the controlunit 103.

In at least one exemplary embodiment, the control unit 103 controls thefirst SPFT switch to connect one resistor of the first switch resistorRp1, the second switch resistor Rp2, the third switch resistor Rp3, andthe fourth switch resistor Rp4, in accordance with the power requirementof the external powered device, in order to set the first predeterminedvalue.

In at least one exemplary embodiment, the second comparing unit 1024comprises a sixth resistor R6 with a sixth resistor first end and asixth resistor second end, a seventh resistor R7 with a seventh resistorfirst end and a seventh resistor second end, and a fifth switch resistorRp5 with a fifth switch resistor first end and a fifth switch resistorsecond end. The second comparing unit 1024 also comprises a sixth switchresistor Rp6 with a sixth switch resistor first end and a sixth switchresistor second end, a seventh switch resistor Rp7 with a seventh switchresistor first end and a seventh switch resistor second end, and aeighth switch resistor Rp8 with a eighth switch resistor first end and aeighth switch resistor second end. A second Single-Pole-Four-Throwswitch (SPFT switch) S2, a sixth capacitor C6 with a sixth capacitorfirst end and a sixth capacitor second end, and a seventh capacitor C7with a seventh capacitor first end and a seventh capacitor second endare also comprised in the second comparing unit 1024. The secondcomparing unit 1024 also comprises an eighth capacitor C8 with an eighthcapacitor first end and an eighth capacitor second end, and a secondcomparator CP2 with a second comparator first input, a second comparatorsecond input, and a second comparator output.

The seventh resistor first end is coupled to the amplifying unit 1022.The seventh resistor first end is coupled to a second reference voltageVCC2, and the seventh resistor second end is coupled to the sixthcapacitor first end. The sixth capacitor second end is grounded. Thesecond reference voltage VCC2 is further coupled to the fifth switchresistor first end, the sixth switch resistor first end, the seventhswitch resistor first end and the eighth switch resistor first end. Thesecond SPFT switch S2 comprises a second SPFT switch first pin moduleS21, a second SPFT switch second pin module S22 and a second SPFT switchcontrol end S23. The second SPFT switch first pin module S21 is coupledto the fifth switch resistor second end, the sixth switch resistorsecond end, the seventh switch resistor second end, and the eighthswitch resistor second end. The second SPFT switch second pin module S22is coupled to the seventh capacitor first end, and the seventh capacitorsecond end is coupled to the eighth capacitor first end. The eighthcapacitor second end is grounded. The second SPFT switch control end S23is coupled to the control unit 103. The second comparator first input iscoupled to the seventh capacitor first end, the second comparator secondinput is coupled to a connection point between the seventh capacitor C7and the eighth capacitor C8, and the second comparator output is coupledto the control unit 103.

In at least one exemplary embodiment, the control unit 103 controls thesecond SPFT switch S2 to connect one resistor of the fourth switchresistor Rp5, the fifth switch resistor Rp6, the seventh switch resistorRp7, and the eighth switch resistor Rp8, in accordance with the power ofthe external powered device 20, in order to set the second predeterminedvalue.

FIG. 6 illustrates a block diagram of an exemplary embodiment of astandby power supply system. In at least one exemplary embodiment, thestandby power supply system 1 comprises the standby power supply device10 b and at least one external powered device 20. The power supplydevice 10 b supplies power to the external powered device 20 when thepower source of the external powered device 20 is removed or worksabnormally. In the exemplary embodiment, the standby power supply device10 b in FIG. 4 is similar to the standby power supply device 10 b inFIG. 5.

In at least one exemplary embodiment, each of the external powereddevices 20 comprises a load 201, an internal power unit 202, an accessport 203, a first diode D1, a second diode D2, and an information unit204. The internal power unit 202 is coupled to the load 201 to supplypower to the load 201. The access port 203 is configured to coupled toone of the at least one port 100 of the standby power supply device 10b. The standby power supply device 10 b supplies power to the externalpowered device 20 from the access port 203. The first diode D1 has afirst diode anode connected to the access port 20, and a first diodecathode connected to the load 201. The second diode D2 has a seconddiode anode connected to the internal power unit 202, and a second diodecathode connected to the first diode cathode.

The voltage of the internal power unit 202 is higher than the powersupply unit 104, thus, when the internal power unit 202 works normallyand the access port 203 is coupled to the standby power supply device 10b, the first diode D1 and the second diode is turned on. Thus, the load201 is mainly supplied by the internal power unit 202, and the standbypower supply device 20 b is close to the no-load state. When theinternal power unit 202 works abnormally, current of the port 203increases and the first diode D1 turns on, and the second diode D2 turnsoff. When the current of one or multiple ports, for example, the port100 a, exceeds the first predetermined value, and current detection unit100 a outputs the first detection signal to the control unit 103 tocontrol the electrical switch 101 a to maintain connected, the powersupply unit 104 supplies power to the external powered device 20 a fromthe electrical switch 101 a and the first diode D1. Similarly, whenmultiple internal power units 202 of the powered device 20 workabnormally, the standby power supply device 10 b supplies power tomultiple powered devices 20 simultaneously.

The information unit 204 is coupled to the access port 203 and theinternal power unit 202. The information unit 204 provides power of theinternal power unit 202 and the priority level information of theexternal powered devices 20. In the exemplary embodiment, theinformation unit 204 provides power of the internal power unit 104 andthe priority level information of the external powered devices 20 inbinary encoding. For example, binary 11 represents power 300 W, binary10 represents power 200 W, and binary 01 represents power 0 W. Binary 11represents the highest priority level, and so on, binary 00 representsthe lowest priority level. When the internal power units 202 of multipleexternal powered devices 20 works abnormally, the standby powered device10 b gives priority to a highest level external powered device 20.

FIG. 7 illustrates an effect diagram of an exemplary embodiment of astandby power supply system. Each circle represents the standby powersupply device 10 b, and each line with a binary number represents thepowered device 20. The standby power supply device 10 b in each circlehas a different power, since the standby power supply device 10 b hassupplied power to the powered device 20 which is powered off. In atleast one exemplary embodiment, when the external powered device 20 ispowered off, the standby power supply device 10 b supplies power to theexternal powered device 20 until the surplus power of the standby powersupply device 10 b is not enough to power supply to a subsequentexternal powered device 20. For example, the total power of the standbypowered device 10 b is 700 W (111), when the external powered device 20with power 300 W(11) is powered off, the standby power supply device 10b consumes 300 W power, resulting in the surplus power being 400 W(100). When another external powered device 20 with power 100 W (01) isalso powered off, the standby power supply device 10 b consumes 100 Wpower again, resulting in the surplus power being 300 W (011). Whenanother external powered device 20 with power 300 W (11) is also poweredoff, the standby power supply device 10 b consumes 300 W power again,resulting in the surplus power being 0 W (000). Thus the surplus powerof the standby power supply device 10 b is not enough to power supply toa subsequent external powered device 20.

FIG. 8 illustrates an effect diagram of another exemplary embodiment ofa standby power supply system. Each circle represents the standby powersupply device 10 b, and each line with a binary number represents thepowered device 20. The standby power supply device 10 b in each circlehas a different power, since powered device 20 which is powered off isrestored. In at least one exemplary embodiment, when power is restoredto the external powered device 20, the power of standby supply device 10b is recovered. For example, the surplus power of the standby powersupply device 10 b is 0 W (000), which represents all of the power ofthe standby power supply device 10 b being supplied to the externalpowered device 20. When standby power is no longer supplied to theexternal powered device 20, with power 300 W (11), the surplus power ofthe standby power supply device 10 b is 300 W (011). When anotherexternal powered device 20 with power 300 W (11) is also restored, thesurplus power of the standby power supply device 10 b is 600 W (011).

The standby power supply device and the standby power supply systemdetect the current of the port 100 by the current detection unit 102.When the current exceeds the first predetermined value, the processingunit 1032 controls the power supply unit 104 to supply power to theexternal powered device 20. When multiple current detection units 102detect that the current of the corresponding port 100 is exceeding thefirst predetermined value, the processing unit 1032 controls the powersupply unit 104 to supply power to the multiple external powered devices20 simultaneously. The control unit 103 also determines whether thestandby power supply device 10 can continue supplying power to asubsequent external powered device 20 according to the surplus power ofthe standby power supply device 10 and the power of the external powereddevice 20.

Many details are often found in the art such as the other features ofthe standby power supply device and the standby power supply system.Therefore, many such details are neither shown nor described. Eventhough numerous characteristics and advantages of the present technologyhave been set forth in the foregoing description, together with detailsof the structure and function of the present disclosure, the disclosureis illustrative only, and changes may be made in the detail, especiallyin matters of shape, size, and arrangement of the parts within theprinciples of the present disclosure, up to and including the fullextent established by the broad general meaning of the terms used in theclaims. It will therefore be appreciated that the exemplary embodimentsdescribed above may be modified within the scope of the claims.

What is claimed is:
 1. A standby power supply device comprising: aplurality of ports, wherein each of the plurality of ports accesses anexternal powered device; a plurality of current detection unitsrespectively coupled to the plurality of ports, wherein the plurality ofcurrent detection units detect current of each port, and when thecurrent of one port of the plurality of ports exceeds a firstpredetermined value, a corresponding current detection unit outputs afirst detection signal; a power supply unit supplying power to theexternal powered device; a control unit coupled to the plurality ofports, the plurality of current detection unit, and the power supplyunit, wherein the control unit controls the power supply unit to supplypower to the external powered device when the control unit receives thefirst detection signal from a corresponding current detection unit;wherein when the control unit receives multiple first detection signals,the control unit controls the power supply unit to supply power tomultiple corresponding external powered devices simultaneously, and thepower supply unit comprises a power information unit coupled to thecontrol unit, and the power supply unit provides the power of the powersupply unit to the control unit.
 2. The standby power supply device ofclaim 1, wherein the control unit comprises: a plurality of portmanagement units correspondingly coupled to the plurality of ports,wherein the plurality of port management units obtains the power of theexternal powered device and priority level information of the externalpowered device; a processing unit coupled to the plurality of portmanagement units, wherein the processing unit controls the power supplyunit to supply power to the corresponding external powered device whenthe processing unit receives the first detection signal; and a powercalculation unit coupled to the power information unit and the pluralityof port management units, wherein the power calculation unit calculatesa surplus power according to the power of the power supply unit and thepower of the external powered device, and the power calculation unitfurther determines whether the power supply unit continue to supplyingpower to a subsequent external powered device according to the surpluspower.
 3. The standby power supply unit of claim 2, wherein when theprocessing unit receives the multiple first detection signals, theprocessing unit controls the power supply unit to preferentially supplypower to an external powered device with a highest priority level.
 4. Astandby power supply device comprising: a plurality of ports, whereineach of the plurality of ports accesses an external powered device; aplurality of current detection units respectively coupled to theplurality of ports, wherein the plurality of current detection unitsdetect current of each port, and when the current of one port of theplurality of ports exceeds a first predetermined value, a correspondingcurrent detection unit outputs a first detection signal; a power supplyunit supplying power to the external powered device; a control unitcoupled to the plurality of ports, the plurality of current detectionunit, and the power supply unit, wherein the control unit controls thepower supply unit to supply power to the external powered device whenthe control unit receives the first detection signal from acorresponding current detection unit; and a plurality of electricalswitch coupled to the plurality of ports, the plurality of portmanagement units, and the power supply unit; wherein when the externalpowered device is connected to the port, a electrical switchcorresponding to the port is turned on; wherein when the control unitreceives multiple first detection signals, the control unit controls thepower supply unit to supply power to multiple corresponding externalpowered devices simultaneously, and when the processing unit receives atleast one first detection signal from the plurality of current detectionunits, at least one corresponding port management unit keepscorresponding electrical switch turn on to control the power supplyunit, such that power is supplied to the corresponding external powereddevice from corresponding electrical switch.
 5. The standby power supplydevice of claim 4, wherein at least one of the plurality of currentdetection units outputs a second detection signal to the correspondingport management unit when the at least one of the current detection unitdetects the current of the corresponding port exceeding a secondpredetermined value; the corresponding port management unit controls thecorresponding electrical switch to turn off when the corresponding portmanagement unit receives the second detection signal from the at leastone current detection unit; and when the duration of the correspondingelectrical switch being turned off exceeds a first predetermined time,the corresponding port management unit controls the correspondingelectrical switch to turn on; wherein the first predetermined value andthe second predetermined value are set in accordance with the power ofthe external powered device.
 6. The standby power supply device of claim5, wherein each of the plurality of current detection units comprises:an obtaining unit coupled to the corresponding port, wherein theobtaining unit obtains current from the corresponding port; anamplifying unit coupled to the obtaining unit, wherein the amplifyingunit amplifies the current; a first comparing unit coupled to theamplifying unit and the processing unit, wherein the first comparingunit outputs the first detection signal to the control unit when thecurrent exceeds the first predetermined value; and a second comparingunit coupled to the amplifying unit and the control unit, wherein thesecond comparing unit outputs the second detection signal to the controlunit when the current exceeds the second predetermined value.
 7. Astandby power supply system comprising a standby power supply device anda plurality of external powered devices, wherein the standby powersupply device comprises: a plurality of ports, wherein each of theplurality of ports accesses an external powered device; a plurality ofcurrent detection units respectively coupled to the plurality of ports,wherein in the plurality of current detection units detect current ofeach port, and when the current of one of the plurality of ports exceedsa first predetermined value, a corresponding current detection unitoutputs a first detection signal; a power supply unit supplying power tothe external powered device; a control unit coupled to the plurality ofports, the plurality of current detection units, and the power supplyunit, wherein the control unit controls the power supply unit to supplypower to the external powered device when the control unit receives thefirst detection signal from the corresponding current detection unit;wherein when the control unit receives multiple first detection signals,the control unit controls the power supply unit supply power to multiplecorresponding external powered devices simultaneously, and the powersupply unit comprises a power information unit coupled to the controlunit, and the power supply unit provides power of the power supply unit.8. The standby power supply system of claim 7, wherein each of theplurality of external powered devices comprises: a load; an internalpower unit coupled to the load, supplying power to the load; an accessport is configured to coupled to one of the plurality of ports of thestandby power supply device; a first diode with a first diode anodecoupled to the access port, and a first diode cathode coupled to theload; a second diode with a second diode anode coupled to the internalpower unit, and a second diode cathode coupled to the first diodecathode; an information unit coupled to the access port and the internalpower unit, wherein the information unit provides power of the internalpower unit and the priority level information of the external powereddevice.
 9. The standby power supply system of claim 8, wherein voltageof the internal power unit is higher than the voltage of the powersupply unit, when the internal power unit supplies power normally, thefirst diode and the second diode are turn on, thereby the load is mainlypowered by the internal power unit and the standby power supply deviceis close to a no load state; and when the current of at least one of theplurality of ports exceeds the first predetermined value, the firstdiode turns on, the second diode turns off, thereby, correspondingcurrent detection unit output the first detection signal to the portmanagement unit to control the corresponding electrical switch to keepon, thereby the power supply unit supplies power to the correspondingexternal powered device from the corresponding electrical switch and thefirst diode.
 10. The standby power supply system of claim 7, wherein thecontrol unit comprises: a plurality of ports port management unitsrespectively coupled to the plurality of ports, wherein the plurality ofports port management units obtain the power of the external powereddevice and priority level information of the external powered device; aprocessing unit coupled to the plurality of port management unit,wherein the processing unit controls the power supply unit to supplypower to the corresponding external powered device when the processingunit receives the first detection signal; and a power calculation unitcoupled to the power information unit and the plurality of portmanagement units, wherein the power calculation unit calculates asurplus power according to the power of the power supply unit and thepower of the external powered device, and the power calculation unitfurther determines whether the power supply unit continue to supplypower to a subsequent external powered device according to the surpluspower.
 11. The standby power supply system of claim 10, when the controlunit receives the multiple first detection signals, and the processingunit controls the power supply unit to preferentially supply power to anexternal powered device with a highest priority level.
 12. The standbypower supply system of claim 7, further comprising: a plurality ofelectrical switches coupled to the plurality of ports correspondingly,the plurality of port management units and the power supply unit,wherein when the external power device is connected to one of theplurality of ports, one of the plurality of electrical switchescorresponding to the port being turned on; and when the processing unitreceives at least one first detection signal from the plurality ofcurrent detection unit, corresponding port management unit keep thecorresponding electrical switch turned on to control the power supplyunit, and the power supply unit supplies power to the correspondingexternal powered device from the corresponding electrical switch. 13.The standby power supply system of claim 12, wherein at least one of theplurality of current detection units outputs a second detection signalto the corresponding port management unit when the at least one of thecurrent detection unit detects the current of the corresponding portexceeding a second predetermined value; and the corresponding portmanagement unit controls the corresponding electrical switch to turn offwhen the corresponding port management unit receives the seconddetection signal from the at least one current detection unit; when theduration of the corresponding electrical switch being turned off exceedsa second predetermined time, the corresponding port management unitcontrols the corresponding electrical switch to turn on; wherein thefirst predetermined value and the second predetermined value are set inaccordance with the power of the external powered device.
 14. Thestandby power supply system of claim 13, wherein each of the pluralityof current detection units comprises: a obtaining unit coupled to thecorresponding port, wherein the obtaining unit obtains current from thecorresponding port; an amplifying unit coupled to the obtaining unit,wherein the amplifying unit amplifies the current; a first comparingunit coupled to the amplifying unit and the processing unit, wherein thefirst comparing unit outputs the first detection signal to the controlunit when the current exceeds the first predetermined value; and asecond comparing unit coupled to the amplifying unit and the controlunit, wherein the second comprising unit outputs the second detectionsignal to the control unit when the current exceeds the secondpredetermined value.